1 Division of Cardiology, Department of Internal Medicine, Daejeon St. Mary's Hospital, The Catholic University of Korea, Daejeon, Korea.
2 Division of Cardiology, Department of Internal Medicine, Yeouido St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea.
3 Division of Cardiology, Department of Internal Medicine, Daejeon St. Mary's Hospital, The Catholic University of Korea, Daejeon, Korea. pmw6193@catholic.ac.kr.